Add cloud_print to the GN build.

cloud_print/common/common.gyp

 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 {
   'variables': {
     'chromium_code': 1,
   },
   'targets': [
     {
+      # GN version: //cloud_print/common:install_utils
       'target_name': 'cloud_print_install_lib',
       'type': 'static_library',
       'dependencies': [
         '<(DEPTH)/base/base.gyp:base',
       ],
       'sources': [
         '<(DEPTH)/cloud_print/common/win/install_utils.cc',
         '<(DEPTH)/cloud_print/common/win/install_utils.h',
       ],
     },
   ],
 }